It’s also possible you changed the bot’s name or you have not invited your bot to a channel in the chat client.

If you’re sending bot a private message instead of messaging it in a channel,
do not prepend ! (a known Hubot limitation). In private messages help
will work, but !help will not; in channels it’s the other way around.

Hubot is online, you can see st2 commands, but saying something like !st2listactions
either throws an error, or gives an acknowledgement message without result, or no response at all.

Possible reasons:

No response at all:

Usually the command you’re trying to run has a typo, or the syntax is incorrect.
Double-check it, and glance over the alias yaml definition to check what the
command syntax is exactly.

Throws an error (no acknowledgement):

Should be debugged according to the error, could be both client-side and server-side,
or an alias problem. Normally, a look into an error or logs will give you ideas on
how to proceed.

Gives an acknowledgement message without result:

If you get an acknowledgement message, but then nothing happens, Hubot is most likely
disconnected from StackStorm stream. The main reason for it is a wrong
networking setup (Hubot can’t connect to your StackStorm instance); check nginx
configuration and the parameters in /opt/stackstorm/chatops/st2chatops.env
(most importantly, ST2_HOSTNAME).
Another reason is that either the StackStorm action you’re trying to launch or your alias
fails with an unexpected error that the bot can’t process. This can be checked in
StackStorm execution history through CLI or Web UI.

Gives an acknowledgement message, then an error:

If the default commands (like !st2listactions) run fine, but your own
aliases throw errors, format of your alias or the underlying action is most
likely the problem. Debug according to the error.

Bonus: have you tried turning it off and on again?

sudost2ctlrestart or sudost2ctlreload--register-all sometimes seem to
magically fix problems, often quite unexpectedly. Restarting just the
st2chatops service also works sometimes: sudoservicest2chatopsrestart.

If problem persists, there’s likely a back-end problem. Make sure other parts of StackStorm
are working properly. Try Step 6 and Step 7 of the
self-check script :

You can run StackStorm commands (and your own aliases) via your bot,
but you can’t trigger chatops.post_message action manually from CLI or Web UI.

Possible reasons:

Some of your action parameters (route, channel, etc) are incorrect. Take a look at chatops.post_result workflow
execution from any chat command you issued before, and repeat every parameter in chatops.post_message
(the last step of the workflow) as is.

st2runchatops.post_messagechannel=<channel_name> to post on a channel. This step
assumes that a bot was created and invited it to the channel on chatops application.

st2runchatops.post_messagechannel=<username>whisper=True to post to a user. Note
that some chat services have limitations on private messages from bots to users (e.g. in
Slack a bot can’t initiate a new conversation).

By now you should have your bot up and running. If not, then just ask for help!